Remove #ifdef CONFIG_ARCH_SUPPORTS_AOUT from <linux/a.out.h>

This file is only included where it makes sense now, so there's no need
for the CONFIG_ARCH_SUPPORTS_AOUT conditional -- and that conditional is
bad, because we want to export <linux/a.out.h> to userspace.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>